The invention relates to an optical device for at least bispectral imaging. In particular, the invention relates to a panoramic periscope having a panoramic head in which is mounted a viewing mirror movable in elevation and azimuth which has an at least bispectral front window, and having a tube in which are arranged a plurality of, and preferably at least three, different measuring or observation devices, the viewing mirror directing their beam paths coaxially through the front window.
German Patent 2,746,076 discloses a panoramic periscope having a switchable daylight and thermal optical imaging system which has a transmitting entrance window for both spectrum ranges, downstream of which is arranged a viewing mirror movable in elevation and azimuth which directs the imaging beams coaxially onto the imaging optics associated with them. A front objective of germanium having a central bore and a front diaphragm are arranged between the viewing mirror and the input objective for the daylight optical imaging system. The gemanium component with a central bore serves as the front objective for the IR beam and allows the visual beam to pass. Although this component remains in position for observation of both the visual spectrum range or the IR spectrum range, various other optical elements must be inserted or removed when switching from the daylight to the thermal optical imaging system or from the thermal to daylight system. A distance-measuring device is not provided in this known arrangement.
German Offenlegungsschrift 3,515,428 discloses a panoramic periscope with change of magnification, laser range-finder and night observation member. The periscope has a viewing head with a gyrostabilized viewing mirror movable about an elevation axis and an azimuth axis, a lower part with an eyepiece system, and a central part which is arranged firmly on a mount and on the one hand carries the viewing head and on the other hand is used for securing the lower part. The central part of this known periscope contains a fixed principal optical system of the apparatus arranged downstream of the viewing mirror, for daylight and night observation, for laser reception and at least in part for the change of magnification and further optical components upstream of a spectrum divider. The space requirement of this arrangement is thus relatively large and an optimization of the overall optical systems for the daylight and IR range is difficult because the principal optical system is fixed. Another disadvantage of this system is that a prism within the system must be inserted when switching from day to night observation.